The present invention relates to an apparatus for filling a fluid food or like liquid into containers each in a specified amount.
Conventional apparatus of the type mentioned include one which comprises a vertical tubular filling nozzle having a valve seat at the edge of an open lower end thereof, a valve upwardly and downwardly movably supported by the filling nozzle and comprising a plug intimately fittable to the valve seat and a stem extending upward from the plug inside the filling nozzle, a spring biasing the valve upward to hold the plug in intimate contact with the valve seat against the gravity acting on the liquid in the filling nozzle, and a metering cylinder for intermittently feeding the liquid into the filling nozzle in a specified amount at a time so as to open the valve by the pressure of downward flow of the liquid against the force of the spring.
If the force of the spring of the apparatus is too great, the valve is difficult to open and the nozzle therefore opens to a small degree, with the result that the liquid flows out at a high speed to entail phenomena undesirable for filling, such as scattering of the liquid. If the spring force is too small, on the other hand, the open lower end of the nozzle will not be closed completely with the valve, permitting the liquid to drip from the nozzle.
It is considerably difficult to set the force of the spring to a suitable value. Moreover, the spring force must be determined suitably in accordance with the viscosity, temperature, quality, etc. of the liquid every time a different kind of liquid is to be filled, or different filling nozzles need to be prepared for the different kinds of liquids to be filled, hence cumbersomeness.